Methods and apparatus for drywall tools

ABSTRACT

The present invention is directed generally to building tools that are high quality, durable, and in some case lightweight. Various tools may be made, at least in part, using a material including magnesium to reduce the weight of the tool. For example, a trowel includes a tang, support member or attachment member that may be made, at least in part, of a magnesium material so as to create a more light weight trowel. The tang, support member or attachment member connects the trowel handle to the trowel blade. The trowel blade may be made of a steel material or a high carbon steel material for high durability. The trowel may be, for example, a concrete trowel including a cross-ground trowel, a flat back end finishing trowel, or a round/round finishing trowel.

This application is a divisional application of U.S. patent applicationSer. No. 10/937,561, filed on Sep. 10, 2004, now abandoned and claimspriority thereto, and claims the benefit of U.S. Provisional ApplicationNos. 60/502,288, filed Sep. 12, 2003, and 60/527,515, filed Dec. 8,2003, all of which are hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention pertains to methods and various apparatuses forbuilding tools. For example, the invention involves methods and variousapparatuses for high quality, durable and in some cases lightweightbuilding tools.

BACKGROUND

Various tools have been known in the past for working with cements,concretes, mastics and/or muds to, for example, prepare, apply andfinish a desired shape or smooth surface for various building surfaces.For example, some tools used for preparing the surface of, for example,concrete, include trowels. Another example are various tools used toprepare and finish, for example, mastics and mud for drywall, includingcorner finishing boxes, joint boxes, and automatic taper machines. Inany case, these types of tools are typically hand tools that are used toapply and/or smooth various building surfaces such as floors and wallsand result in skilled craftsman working on a number of surfaces for longperiods of time during the work day. These types of tools are alsoexposed to bumps and mechanical stresses as well as corrosive substancesin their use. Therefore, it is advantageous to build such tools to becost effective, light in weight and durable against extensive use andstress as well as the corrosion from corrosive materials they aredesigned to work on (e.g., concrete, mastic, mud, etc.).

SUMMARY

The present invention is directed generally to building tools that arehigh quality, durable, and in some cases lightweight. For example,various tools may made by forming multiple sections into a singleintegrated piece by, for example, casting the parts using a moldingprocess so as to reduce manufacturing cost and increase the structuraldurability of the tool. Further, various tools may be made, at least inpart, using a material including magnesium to reduce the weight of thetool. Still further, various tools may be made using one or moreprotective coatings for protecting various metals against corrosion, forexample, using a high impact coating such as paint covered with a clearcoat of lacquer.

In one embodiment, a flat box may include a housing or container forholding mastic or mud and may be formed in most part from a singlemolded metal container. A movable pressure plate is placed in a firstopening of the housing or container so as to provide a mechanism forpushing mastic or mud place in the container out an output hole of thecontainer or housing so as to apply the mastic or mud in a controlledmanner to a building surface. A back plate may complete the ridgedstructure of the housing or container and may be attached to the housingor container by, for example, welding. The back plate may be made as asingle flat plate having a relatively short width so as to allow themovable pressure plate to open sufficiently wide to allow residualmastic or mud to be removed from the inside of the housing or container(i.e., to easily clean out residual mastic or mud after use) without theneed for removing the pressure plate or removing various sides of thecontainer or housing. The housing or container, pressure plate, and/orvarious other parts of the flat box may be made of metal including, forexample, aluminum so as to make the flat box light weight. In onevariation, the housing, pressure plate, and/or various other parts ofthe flat box may be coated with a high impact coating and/or a lacquer,for example a high impact lacquer paint so as to provide a corrosionresistant coating. In another variation, the housing or container,pressure plate, and/or various other parts of the flat box may be madeof metal including, for example, magnesium so as to make the flat boxeven lighter weight. In this case, larger housings or containers havinga higher volume capacity may be made without becoming too heavy for atypical user or tradesman.

In another embodiment, an angle or corner applicator may include ahousing or container for holding mastic or mud and may be formed, inmost part, from a single molded metal container. A movable pressureplate may be placed in a first opening of the housing or container so asto provide a mechanism for pushing mastic or mud place in the containerout an output hole or opening of the container or housing so as to applythe mastic or mud in a controlled manner to a building surface. Themovable pressure plate may be attached to the housing or container. Thehousing or container and/or various other parts of the angle or cornerapplicator may be made of a metal including, for example, aluminum so asto make angle or corner applicator light weight. In one variation, thehousing or container and/or various other parts of the angle or cornerapplicator may be coated with a high impact coating and/or a lacquer,for example a high impact lacquer paint so as to provide a corrosionresistant coating. In another variation, the housing or container,pressure plate, and/or various other parts of the angle or cornerapplicator may be made of metal including, for example, magnesium so asto make the angle or corner applicator even lighter weight. In thiscase, larger housings or containers having a higher volume capacity maybe made without becoming too heavy for a typical user or tradesman.

In a further embodiment, an automatic taper may include a control tubecoated with a high impact coating and/or a lacquer, for example a highimpact lacquer paint, so as to provide a corrosion resistant coating.

In a further embodiment, a trowel includes a tang, support member orattachment member that may be made, at least in part, of a magnesiummaterial so as to create a more light weight trowel. The tang, supportmember or attachment member connects the trowel handle to the trowelblade. The trowel may be, for example, a concrete trowel including across-ground trowel, a flat back end finishing trowel, or a round/roundfinishing trowel.

BRIEF DESCRIPTION OF THE DRAWINGS

The objects, features and advantages of the present invention willbecome more readily apparent to those skilled in the art upon readingthe following detailed description, in conjunction with the appendeddrawings, in which:

FIGS. 1A-1D depict a first traditional flat box construction;

FIG. 2 illustrates a second traditional flat box construction;

FIGS. 3A and 3B are perspective views of an exemplary flat box orapplicator, according to one embodiment of the invention;

FIG. 4 is a detailed assembly drawing for the exemplary flat box orapplicator of FIGS. 3A and 3B, according to one embodiment of theinvention;

FIG. 5 illustrates a perspective view of an exemplary corner or angleapplicator box, according to one embodiment of the invention;

FIG. 6 depicts a first detailed assembly drawing for the exemplarycorner or angle applicator box of FIG. 5, according to one embodiment ofthe invention;

FIG. 7 depicts a second detailed assembly drawing for the exemplarycorner or angle applicator box of FIG. 5, according to one embodiment ofthe invention;

FIG. 8 depicts a perspective view of an exemplary automatic taper,according to one embodiment of the invention;

FIGS. 9A-9C depicts a number of exemplary trowels, according to oneembodiment of the invention; and

FIG. 10 illustrates one exemplary tang, support member, or attachmentmember for the trowel of FIGS. 9A-9C, according to one embodiment of theinvention.

DETAILED DESCRIPTION

The present invention is directed generally to building tools that arehigh quality, durable, and in some cases lightweight. As such, thepresent invention includes various embodiments showing methods andvarious apparatuses for working with mastic or mud and/or finishingdrywall. One embodiment is directed to a flat box applicator typicallyused for applying mastic or mud to complete drywall.

Referring to FIGS. 1A, 1B, 1C, and 1D a first type of typical flat boxapplicator is shown. Some examples may be found in U.S. Pat. Nos.2,824,442; 2,984,857; 3,888,611; and 4,516,868, among others. Inparticular, the flat box applicator 100 is made in the form of acontainer or housing 60. The housing may have three separate sides 55 a,55 b, and 55 c, forming three sides of a six sided container or housing60. A first side 55 a is bent to form a front lip and front plate. Asecond side portion 55 b is bent into a “C” shape (side profile) in FIG.1D to form a back side plate. A third side 55 c is bent at a slightangle to form a bottom plate. Two additional side portions, side panel28 and side panel 30, cap opposite ends of the first portion 55.Finally, the sixth side of the container our housing 60 is provided by amovable pressure plate 52. A handle 12 is attached to the pressure plate52 by a hinge bracket 72. Side panels 28 and 30 are kept in place bytension rods 56 a-56 c which are threaded on their ends and tensionedwith nuts 42. Wheels 44 are attached to the container or housing 60.

It is noteworthy that the first side portion 55 may be made of aplurality of pieces and that at one end it contains a ridge 40 onportion 55 b that follows the contour of side panel 28 and side panel30, so as to attach tension springs 62 and 64. The ridge 40 also limitsthe upward or backward travel of pressure plate 52 so that when thepressure plate is pulled as far back as possible by the tension ofspring 62 and spring 64 it is limited to only a small opening betweenportion 55A and the lip of pressure plate 52

Traditionally, the container or housing 60 may be made of, for example,a metal and or plastic. In one case, the first side portion 55 andpressure plate 52 may be made of an anodized metal and side panel 28 andside panel may be made of plastic so as to deter corrosion from themastic or mud. In the alternative the pressure plate 52 may be made ofstainless steel.

Referring to FIG. 2, another typical construction of, for example, acorner or angle applicator box 200 is shown. In this case, the sides areheld together using lateral extending members 4 and 7 from an acuteshaped front wall 6 that is receive by openings 5 in side wall 2. Thelateral extending members may be flared or widened at its outer mostedge so that the side wall 2 is mounted securely to front wall 6.Further, in this case the pressure plate or mastic pressing plate C ispivotally mounted with a later shaft D located between parallel sidewalls 1 (opposite 2) and 2. Again the side wall materials may be ananodized metal and/or a plastic to resist corrosion.

Referring now to FIGS. 3A, 3B, and 4, an exemplary flat box orapplicator 300 according to one embodiment of the invention will now bedescribed. In this case, at least four of the five side walls of theflat box or applicator are formed together as an integral piece. Forexample, side walls 305, 310, 315, and 320 may be made into a singleintegrated piece by, for example, casting or molding the parts togetherusing a casting or molding process. Subsequently, a back plate side wall325 may be attached to side walls 305, 310, and 315 by, for example,welding. In one variation, all of side walls 305, 310, 315, 320, and 325may be formed together in an integral piece with side wall 325 being alinear extension of side wall 310. Again, a molding process may be usedto form the integral piece. Subsequently, side 325 maybe bent up to beslightly more than parallel with side wall 320 and welded on its ends toside walls 305 and 315. This may help to reduce manufacturing cost andincrease the structural durability of the tool. Of course, two or moreside walls may be made integral with one another.

The flat box or applicator 300 may also include a movable pressure orpressing plate 350 placed in an opening formed between side walls 305,315, 320 and back plate side wall 325. The movable pressure plate 350provides a mechanism for pushing mastic or mud place in the containerout an output hole formed in lower or bottom side wall 310 of thecontainer or housing, so as to apply the mastic or mud in a controlledmanner to a building surface.

The material of the side walls 305, 310, 315, 320, 325 and pressureplate 350 may be, for example, a metal or plastic. In one variation, theflat box or applicator 300 housing or container walls 305, 310, 315,320, 325 and pressure plate 350 may be made, at least in part, using alight weight material including aluminum or magnesium to reduce theweight. For a flat box housing or container made of a material includingmagnesium, the material may be for example a magnesium alloy such asAZ31C containing approximately the following approximate percentages ofmaterials: Magnesium: Aluminum (Al) at 2.5-3.5%; Copper (Cu) at 0.05%max; Iron (Fe) at 0.005% max; Manganese (Mn) at 0.20% min; Nickel (Ni)at 0.005% max; Silicon (Si) at 0.30% max; Zinc (Zn) at 0.60-1.40%;Calcium (Ca) at 0.30% max; OT (other) at 0.30% max; and Magnesium (Mg)is the remainder %. This composition or alloy of Magnesium may beparticularly useful for forming parts by extrusion. Further, theformulation may have variations from those above, for example, thecomposition of magnesium may vary within the above by +/−5% for Al andMg, and +5% on Mn. Another useful magnesium compound or alloy, mayinclude the following substances in the following amounts: Aluminum (Al)at 8.5% to 9.5%; Copper (Cu) at 0.25% maximum; Manganese (Mn) at 0.15%minimum; Nickel (Ni) at 0.01% maximum; Silicon (Si) at 0.20% maximum;Zinc (Zn) at 0.45% to 0.9%; other materials (OT) at 0.30% maximum; andMagnesium (Mg) is the % remainder. This composition of Magnesium may beparticular good for forming parts by casting. Further, otherformulations are possible, such as the formulation of the magnesiumalloy may vary within the above by +/−5% for Al and Mg, and +5% on Mn.In any case, the magnesium alloy does tend to be lighter in weight thanan aluminum alloy, thus the magnesium may be particularly useful formaking higher capacity flat boxes, without having too heavy a tool forthe user when loaded with mastic or mud.

Further, the side walls 305, 310, 315, 320, 325, and pressure plate 350may be covered with one or more protective coatings for protectingvarious metals against corrosion, for example, using a high impactcoating such as paint covered with a clear coat of lacquer. In oneexample, the side walls and pressure plate 350 may be formed, powdercoat with a liquid high-impact spray paint, then clear coated with highimpact coating. One detailed coating method may be as follows usingpaints and lacquer finishes typically used to paint and seal the bodyparts of a motor vehicle:

1. Clean the surface

2. Sand blast all surfaces to create slight porosity on surface forpaint adhesion

3. Blow dust and residue off casting. Remove any excess residue withclean cloth

4. Wet spray paint (special metal paint)

5. Bake 1 hour at 120 degree C.

6. Cool flat boxes to room temperature

7. Paint with wet clear coat paint specially designed to seal coloredpainted surface.

8. Bake 1 hour at 120 degree C.

9. Cool

These surface treatment methods will help seal and resist corrosion fromthe mastic or mud used in the flat box 300 for working on drywall orother surfaces.

In one variation, the back plate side wall 325 may be made as a singleflat plate having a relatively short width or height from bottom sidewall 310, so as to allow the movable pressure plate 350 to opensufficiently wide with respect to the housing to allow residual masticor mud to be removed from the inside of the housing or container (i.e.,to easily clean out residual mastic or mud after use) without the needfor removing the pressure plate or removing various sides of thecontainer or housing. As compared with the flat box show in FIGS. 1A-1C,the present invention may not have an additional length 40 on the backplate side wall 325 and the pressure plate 350 may therefore open widerfor cleaning. This supports cleaning of the single integrated walldesign for the flat box 300 that may not be taken apart as a result ofits design. In an embodiment, two screws 360 may be placed through theside wall 310 as shown in FIG. 4 such that the ends of the screws 360protrude from the interior of wall 310 sufficiently to stop outwardmovement of the movable pressure plate 350 upon the movable pressureplate 350 reaching an open position responsive to springs 370. Thesprings 370 may be biased to urge the movable pressure plate 350 to theopen position. In an embodiment, the movable pressure plate 350 may bemaintained in a closed position by clips 375. The screws 360 acting incooperation with the springs 370 may thereby prevent the movablepressure plate 350 from becoming detached from the housing or containerwhile in the open position. The screws 360 may also operate to secure awheel assembly mounting bracket 365 to the housing or container.Therefore, in this embodiment, the flat box or applicator 300 mayinclude a housing or container for holding mastic or mud that may beformed in most part from a single molded metal or plastic containerincluding side walls 305, 310, 315, 320, and possibly back plate 325,and a pressure plate 350 included therewith.

One variation of the manufacturing process for making an applicator boxmay be as follows. Cast or mold the aluminum or magnesium boxes, weld inthe back plate, powder coat, and then clear coat with high impactcoating. From there the applicator boxes may be drilled and tapped toadd the other parts.

In another embodiment, shown in FIGS. 5, 6, and 7, an angle or cornerapplicator box 500 may include a housing or container 490 for holdingmastic or mud and may be formed, in most part, from a single moldedmetal container. A movable pressure plate 491 may be placed in a firstopening of the housing or container so as to provide a mechanism forpushing mastic or mud place in the container out an output hole oropening of the container or housing 490 that may be capped by a cone 413so as to apply the mastic or mud in a controlled manner to a buildingsurface. The movable pressure plate 491 may be attached to the housingor container 490 via a shaft 410. The housing or container and/orvarious other parts of the angle or corner applicator 500 may be made ofa metal including, for example, aluminum so as to make angle or cornerapplicator 500 light weight. In one variation, the housing or container490 and/or various other parts of the angle or corner applicator 500 maybe coated with a high impact coating and/or a lacquer, for example ahigh impact lacquer paint as shown in the previous embodiment, so as toprovide a corrosion resistant coating. In another variation, the housingor container 490, pressure plate 491, and/or various other parts of theangle or corner applicator may be made of metal including, for example,magnesium so as to make the angle or corner applicator 500 even lighterweight. In such embodiments, the housing or container 490, pressureplate 491, and/or various other parts of the angle or corner applicatormay be made using one of the magnesium alloys described hereinabove. Inthis case, larger housings or containers having a higher volume capacitymay be made without becoming too heavy for a typical user or tradesman.Of course, various portions or parts of the angle or corner applicatormay be made of a plastic material.

In a further embodiment shown in FIG. 8, an automatic taper 805 mayinclude a shaft 815 including a control tube portion 810 and a tapeapplication and cutting mechanism 820 attached to an end of the shaft815 and responsive to the control tube 810. In an embodiment, thecontrol tube 810 may be coated with a high impact coating and/or alacquer, for example a high impact lacquer paint, so as to provide acorrosion resistant coating. This high impact coating may be similar tothe high impact coating described above. In tool operation, the controltube is used for cutting and advancing tape for drywall taping.

In a further embodiment shown in FIGS. 9A-9C and 10, a trowel 900 mayinclude a tang, support member or attachment member 950 that may bemade, at least in part, of a material including magnesium so as tocreate a more light weight trowel. The material including magnesium maybe magnesium alloy. For example, a magnesium alloy such as AZ31Ccontaining approximately the following approximate percentages ofmaterials: Magnesium: Al: 2.5-3.5%; Cu: 0.05% max; Fe 0.005% max; Mn0.20% min; Ni 0.005% max; Si 0.30% max; Zn 0.60-1.40%; Ca 0.30% max; OT0.30% max; Mg the remainder %. This composition or alloy of Magnesiummay be particularly useful for forming parts by extrusion. Further, theformulation may have variations from those above, for example, thecomposition of magnesium may vary within the above by +/−5% for Al andMg, and +5% on Mn. Another useful magnesium compound or alloy, mayinclude the following substances in the following amounts: Aluminum (Al)at 8.5% to 9.5%; Copper (Cu) at 0.25% maximum; Manganese (Mn) at 0.15%minimum; Nickel (Ni) at 0.01% maximum; Silicon (Si) at 0.20% maximum;Zinc (Zn) at 0.45% to 0.9%; other materials (OT) at 0.30% maximum; andMagnesium (Mg) is the % remainder. This composition of Magnesium may beparticular good for forming parts by casting. Further, otherformulations are possible, such as the formulation of the magnesiumalloy may vary within the above by +/−5% for Al and Mg, and +5% on Mn.The tang, support member or attachment member 950 connects the trowelhandle 910 (910A, 910B, 910C) to the trowel blade 905 (905A, 905B,905C). The trowel 900 may be, for example, a concrete trowel including across-ground trowel 905A, a flat back end finishing trowel 905B, or around/round finishing trowel 905C. The trowel blade 905 may be made ofhigh carbon steel covered with a clear coat.

Referring to FIG. 10, the tang, support member or attachment member 950includes an elongated member 951 that is coupled at its lower surface952 to the trowel blade 905. A handle connecting member 953 may beincluded with the tang, support member, or attachment member 950, andmay be coupled to and approximately perpendicular to the elongatedmember 951. A handle support member 954 may be included with the tang,support member, or attachment member 950, and may be attached to thehandle connecting member 953 and approximately parallel with theelongated member 951. The elongated member 951, handle connecting member953, and handle support member 954, may be part of an integral tang,support member, or attachment member 950 made of the same material ormay be welded together and made of the same or different materials suchas materials including steel and/or magnesium. Of course, a tang oflightweight magnesium alloy may be useful in coupling a blade and ahandle for a variety of other tools.

Although a particular embodiment(s) of the present invention has beenshown and described, it will be understood that it is not intended tolimit the invention to the preferred embodiment(s) and it will beobvious to those skilled in the art that various changes andmodifications may be made without departing from the spirit and scope ofthe present invention. Thus, the invention is intended to coveralternatives, modifications, and equivalents, which may be includedwithin the spirit and scope of the invention as defined by the claims.

All publications and patents cited herein are hereby incorporated byreference in their entirety for all purposes.

What is claimed is:
 1. A construction trowel for preparing, applying,and/or finishing various cements, concretes, mastics and/or muds tovarious building surfaces, comprising: a handle; a blade made of highcarbon steel; and a tang connected to the handle and blade and made, atleast in part, of a metal including magnesium so that the trowel may bemade lightweight.
 2. The trowel of claim 1, wherein the metal is amagnesium alloy.
 3. The trowel of claim 2, wherein the magnesium alloyconsist of metal that includes magnesium in the range of approximately95.74% to 90.74%.
 4. The trowel of claim 3, wherein the metal furtherincludes aluminum.
 5. The trowel of claim 4, wherein the material is amagnesium alloy consisting of: aluminum at approximately 2.5-3.5%;copper at approximately 0.05% maximum; iron at approximately 0.005%maximum; manganese at approximately 0.20% minimum; nickel atapproximately 0.005% maximum; silicon at approximately 0.30% maximum;zinc at approximately 0.60-1.40%; calcium at approximately 0.30%maximum; other materials at approximately 0.30% maximum; and magnesiumis the remainder %.
 6. The trowel of claim 2, wherein the magnesiumalloy consist of metal that includes magnesium in the range of 93.69% to83.69%.
 7. The trowel of claim 6, wherein the metal further includesaluminum.
 8. The trowel of claim 7, wherein the material is magnesiumalloy consisting of: aluminum at 8.5-9.5%; copper at 0.25% maximum;manganese at 0.15% minimum; nickel at 0.01% maximum; silicon at 0.20%maximum; zinc at 0.45%-0.9%; other materials at 0.30% maximum; andmagnesium is the remainder %.
 9. The trowel of claim 1, wherein the tangincludes: an elongated member; a handle connecting member coupled to andapproximately perpendicular to the elongated member; and a handlesupport member coupled to the handle connecting member, the handlesupport member being approximately parallel with the elongated member,and wherein only one of the elongated member, the handle connectingmember and the handle support member include magnesium.
 10. The trowelof claim 1, wherein the tang includes: an elongated member; a handleconnecting member coupled to and approximately perpendicular to theelongated member; and a handle support member coupled to the handleconnecting member, the handle support member being approximatelyparallel with the elongated member, and wherein only one of theelongated member, the handle connecting member and the handle supportmember include magnesium.
 11. The trowel of claim 1, wherein the tang isa handle-to-blade attachment member and includes an elongated memberportion, a handle connection portion, and a handle support portion andthe blade is attached to an elongated member portion of the tang, thetool further comprising: a handle attached to a handle support memberportion of the tang, wherein only the handle support portion and thehandle connection portion of the tang include magnesium.
 12. A trowel,comprising: a handle; a blade; and a means for connecting the handle tothe blade, wherein the means for connecting the handle to the blade ismade of a magnesium alloy material so as to make the trowel lightweightand the blade is made of a steel or a high carbon steel material so asto be durable.
 13. The trowel of claim 12, wherein the material is amagnesium alloy consisting of: aluminum at 2.5-3.5%; copper at 0.05%maximum; iron at 0.005% maximum; manganese at 0.20% minimum; nickel at0.005% maximum; silicon at 0.30% maximum; zinc at 0.60-1.40%; calcium at0.30% maximum; other materials at 0.30% maximum; and magnesium is theremainder %.
 14. The trowel of claim 12, wherein the means forconnecting the handle to the blade is formed by extrusion.
 15. Thetrowel of claim 12, wherein the material is a magnesium alloy consistingof: aluminum at 8.5-9.5%; copper at 0.25% maximum; manganese at 0.15%minimum; nickel at 0.01% maximum; silicon at 0.20% maximum; zinc at0.45%-0.9%; other materials at 0.30% maximum; and magnesium is theremainder %.
 16. The trowel of claim 15, wherein the magnesium contentmay increase or decrease by 5%.
 17. The trowel of claim 16, wherein themeans for connecting the handle to the blade is formed by a castingprocess.
 18. The trowel of claim 12, wherein the trowel is a concretetrowel that is a cross-ground trowel, a flat back end finishing trowel,or a round/round finishing trowel.
 19. A trowel for buildingconstruction, comprising: a handle; a blade made of high carbon steel;and a tang connecting the handle to the blade, wherein the tang is madeof a material that includes aluminum and magnesium.
 20. The trowel ofclaim 19, wherein the material of the tang is a magnesium alloy that islight-weight so as to reduce the weight of the trowel and the highcarbon steel blade is covered with a clear coat so as to provide highdurability of the blade.